Movement disorders, such as tardive dyskinesias, act as constraints on psychiatric chemotherapy. This project aims to advance our understanding of some of the variables contributing to such disorders and to develop techniques for measuring them precisely. Monkeys will be trained to execute skilled movements that require concurrent extension of legs and flexion of arms. Tremor spectrum, movement accuracy, and allied variables will be measured. The induction of abnormal movements by effort will also be gauged by photographs of the monkeys' faces during movement. These measures will be directed toward the question of dosage schedule. Many patients, either because of specified drug holidays or failure to adhere to prescribed schedules, take drugs intermittently. Such schedules may enhance the eruption of movement disorders. Accordingly, haloperidol will be administered by three dosing schedules: 0.1 mg/kg daily, 0.5 mg/kg weekly, 0.2 mg daily on alternate months. These schedules are designed to elicit variations in responses such as the development of supersensitivity, which coupled with precise measures of motor function, can provide useful information about how movement disorders arise.